Equine Sports Medicine

Gastric Ulceration in Sport Horses

Sport horses tend to be stabled horses, and consequently suffer from one of the most common health problems of the stabled horse - gastric ulceration. We humans have the luxury of a quick trip to the drug store for our favorite heartburn remedy, and we can call our physicians for a more in-depth diagnosis of why we experience such agonizing gastrointestinal pain. Horses can only show us by indirect signs that they are in chronic, debilitating pain. It isn't surprising that gastric ulceration can actually be a cause of poor performance in the sport horse.

What is gastric ulceration?

In any species, we are referring to an erosion, or sloughing of one or multiple areas of the surface layer of the stomach. Gastric ulceration is very common in horses. In various studies, from 70% - 100% of horses examined had endoscopic evidence of gastric ulceration. This, however, does not mean that all of these horses had clinical signs of gastric ulceration. Unlike people, who develop gastric ulcers in response to a bacterial infection, no infectious cause of gastric ulceration has been identified in horses. Few specific causes of gastric ulceration have been clearly identified. However, most practitioners recognize that stress seems to precipitate gastric ulceration in foals; and infrequent feeds of low-roughage, high carbohydrate foods and a high level of training have been implicated in adult horses. Unlike humans, horses secrete gastric acid continuously, whether they are eating or not. In the wild, horses spend the majority of their days continually eating small amounts of relatively poor quality, high roughage food. Continual acid secretion accommodates this natural lifestyle perfectly. When horses are fed large quantities of high quality food infrequently, their stomachs rapidly empty, essentially leaving the stomach with nothing to do. The stomach has a variety of protectant factors against the effects of gastric acid, but when the stomach is empty, the horse's ability to withstand the effects of gastric acid can be overwhelmed. The use of certain anti-inflammatory drugs (such as phenylbutazone ('Bute') or flunixin meglumine (Banamine™) canalso induce gastric ulcers in horses (more on this later). If gastric ulceration becomes severe, the erosions may begin to bleed. Horses can eventually become anemic and low in protein due to losses through the gastric ulcers.   Back to the top

What are the signs of gastric ulceration?

Symptoms associated with gastric ulceration in adult horses may include recurrent or acute colic, decreased appetite, decreased manure production, poor body condition, poor haircoat, poor performance, and a crabby attitude.   Back to the top

How do I find out if my horse has gastric ulcers?

  • The only way to definitively diagnose gastric ulceration is with gastroscopy.
  • Gastroscopy refers to the use of a specialized endoscope - a fiberoptic instrument that essentially allows the use of a camera to visualize structures that are far away. To look at the stomach of an adult horse, we need a gastroscope that is at least 2.2 meters long.
  • With the gastroscope, we look for areas of the stomach lining that have an abnormal appearance - this may range from outright areas of bleeding to areas of eroded or thinned tissue.   Back to the top

How do I prevent gastric ulcers?

  • Horses that have constant access to turnout and roughage in the form of hay or pasture rarely develop gastric ulceration.
  • Horses that are not in training, rarely develop gastric ulceration.
  • We suspect that the best prevention for gastric ulceration is to mimic, as best as possible, the life of a horse at free range. This translates into frequent small meals, a preponderance of roughage in the diet, and plenty of turnout.   Back to the top

Learn more about gastric ulcers (click here)